The technology disclosed herein relates to a lens barrel used in an image-capturing device.
Retractable lens barrels used in image-capturing devices are typically provided with a cam mechanism configured with a cam follower and a cam coupled to the cam follower. In such lens barrels, the cam mechanism is activated mechanically or electrically to change the position of a zoom lens, whereby the magnification factor of the optical system can be varied (see, for example, patent documents 1 to 3 (Japanese Laid-Open Patent Application Publication No. 2002-23036, No. H9-189844 and No. 2010-26322)).